CrNbO Nanowires with High Electronic Conductivity for High-Rate and Long-Life Lithium-Ion Storage.

Intercalation-type TiNbO (x = 2, 5, and 24) anode materials have recently become more interesting for lithium-ion batteries (LIBs) due to their large theoretical capacities of 388-402 mAh g. However, the Ti/Nb ions in TiNbO with empty 3d/4d orbitals usually lead to extremely low electronic conductivity of <10 S cm, greatly restricting their practical capacity and rate capability. Herein, we report a class of highly conductive CrNbO nanowires as an intercalation-type anode material for high-performance LIBs. The as-made CrNbO nanowires show an open shear ReO crystal structure (C2 space group) with 4% tetrahedra and a conducting characteristic with ultrahigh electronic conductivity of 3.6 × 10 S cm and a large Li-ion diffusion coefficient of 2.19 × 10 cm s. These important characteristics make them deliver outstanding electrochemical properties in term of the largest reversible capacity (344 mAh g at 0.1 C) in all the known niobium- and titanium-based anode materials, safe working potential (∼1.65 V vs Li/Li), high first-cycle Coulombic efficiency (90.8%), superior rate capability (209 mAh g at 30 C), and excellent cycling stability, making them among the best for LIBs in niobium- and titanium-based anode materials.